Study reveals magnitude of variation in gene expression measurements within breast cancers

Blogger's Note: while this study is related to breast cancer, the philosophy should be subject to scrutiny in all cancers

~~~~~~~~~~~~~~

ESMO press release:
 
"....One important challenge is the fact that many different cell types can be present within a single tumour (known as intratumoural heterogeneity), each with different patterns of gene expression and potentially different sensitivity to drugs.
"Performing these tests with a single biopsy may or may not accurately represent that cancer, depending on intratumoural heterogeneity," explains lead author Dr Rosanna Lau from the University of Texas MD Anderson Cancer Center, US.
A further complication is that some of the variation between test results can arise from technical variations in the testing process, and not by real differences between samples (analytical variance).....
 
"Developing accurate biomarkers that are not subject to real tumour sampling bias is of critical importance. This intricate study will likely be a gold standard by which other studies in this area are measured. Such in-depth analyses will ultimately be essential in the biomarker qualification process," he said."